| In order to find out the formation procedures and the series of morphology for silicon nitride by the vapor phase reaction, the experiments have been carried out in the temperature range of 200-1550℃ and the various pressures. The reaction products and thermal decomposited powders in the various temperatures and pressures kave been thoroughly investigated by means of X-ray diffraction, infra-red spectroscopy and electron microscopy. As regards to silicon nitride powders, crystallized whisker shaped α-Si₃N₄ was obtained by treating the reaction product formed at 25℃ into 1450℃. At 1550℃ under the pressure of 2.9KPa, hexagonal shaped α-Si₃N₄ was obtained in the thermal decomposition, and rod shaped β-Si₃N₄ in the vapor phase reaction. |
|
